Light emitting diodes refer to inorganic semiconductor devices that emit light generated by recombination of electrons and holes. Particularly, ultraviolet (UV) light emitting diodes have been increasingly used in a variety of fields such as UV curing, sterilization, white light sources, medicines, equipment parts, and the like.
UV light emitting diodes emit light having a relatively short peak wavelength (generally, light having a peak wavelength of 400 nm or less). In fabrication of such UV light emitting diodes, an active layer is formed of a material having band gap energy corresponding to a relatively short peak wavelength in order to emit light of the relatively short peak wavelength. For example, the active layer can be formed of AlGaN containing 10% or more of Al as a nitride semiconductor. In addition, if the band gap energy of n-type and p-type nitride semiconductor layers is lower than energy of UV light emitted from the active layer, the UV light emitted from the active layer can be absorbed into the n-type and p-type nitride semiconductor layers in the light emitting diode. Accordingly, not only the active layer of the UV light emitting diode but also other semiconductor layers disposed in a light emitting direction of the light emitting diode are formed to have an Al content of 10% or more.